Can being on ritalin (methylphenidate) for 20 years cause cognitive impairment and changes in personality? i have these symptoms but stopped my meds 2.5 yrs ago.

Cognitive effects: When prescribed and monitored appropriately, Ritalin (methylphenidate) improves -- not impairs -- cognitive function. Distractibility decreases, and focus increases. Ritalin has even helped people with hypoactive delirium -- not an expected result if the drug causes cognitive impairment. http://tinyurl.com/kypxu2a your symptoms still need assessment even though they're not likely ritalin-caused.

No relationship: The Ritalin (methylphenidate) is not responsible for your current issues, and indeed, you need to have this evaluated by your physician. One possible answer is a sleep disorder, but other issues should be assessed.